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FXUS65 KPUB 261605
AFDPUB
Area Forecast Discussion
National Weather Service Pueblo CO
1005 AM MDT Tue Sep 26 2017
.UPDATE...
Issued at 1002 AM MDT Tue Sep 26 2017
Added some patchy fog/drizzle to plains this morning. FreezeWarning expired for the San Luis Valley at 8 am this morning.
Alamosa hit at least 24 degrees. Leadville was also 24 last night.
&&
.SHORT TERM...(Today and tonight)
Issued at 506 AM MDT Tue Sep 26 2017
Cool air mass remains in place across the eastern mountains and
plains early this morning, as surface high pressure builds south
through the central U.S. Expect mostly cloudy and cool conditions to
persist today and tonight over the eastern half of the area, as weak
E-SE winds continue. Farther west, air mass is drier, and would
expect partly to mostly sunny skies into the afternoon. Precip
chances look rather low during the daytime hours, with perhaps some
light drizzle this morning along and west of I-25, then a few
showers/weak thunderstorms over the mountains and along the NM
border in the afternoon. As southwestern U.S. upper low begins to
lift northward tonight, moisture and vertical motion start to
increase, and would expect showers and thunderstorms to gradually
spread from sw to ne across the area, with highest pops over the San
Juans and srn Sangres.
.LONG TERM...(Wednesday through Monday)
Issued at 506 AM MDT Tue Sep 26 2017
Relatively minor meteorological adjustments needed with this
forecast package with below seasonal maximum temperatures
continuing into Friday in combination with above seasonal pops
also anticipated into at least Friday evening. Then, warmer and
drier conditions are expected this weekend.
Latest longer term computer simulations, forecast model soundings
and PV/precipitable water analysis indicate that unsettled
meteorological conditions will be noted over the forecast district
from Wednesday into Friday evening as healthy closed upper low
initially centered over west-central Arizona Wednesday moves into
north-central Arizona by Wednesday night and then into
northeastern Utah Thursday before shifting into Montana by later
Friday.
It addition, at the surface, varying degrees of a 1024+MB surface
highs centered over Nebraska and Kansas from Wednesday into
Friday evening in combination with the influence of the upper
low will allow a cool and moist meteorological pattern to be
noted over the forecast district from Wednesday into Friday
evening.
Then, warmer and somewhat drier conditions are expected during the
weekend as drier zonal to southwesterly upper flow and eastern
Colorado surface lee-side troughing develops.
At this time, the highest potential for beneficial
precipitation...including lower terrain rain(moderate to heavy at
times), higher elevation snow(moderate to heavy at times) and
isolated thunderstorms at times over the forecast district during
the longer term should be realized from Wednesday into Thursday
night. As always, WFO Pueblo will monitor closely and issue
meteorological highlights as needed.
As touched upon earlier, below seasonal late September maximum
temperatures are expected to continue over the majority of the
forecast district from Wednesday into Friday, with maximum
temperatures then climbing to near to slightly above late
September/early October climatological averages this weekend,
while projected minimum temperatures generally remain above
seasonal averages during the longer term. Finally, the highest
potential for stronger gradient winds during the longer term
should be experienced from Saturday evening into Monday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 506 AM MDT Tue Sep 26 2017
At KALS...could see a brief period of low clouds/fog near the
terminal around sunrise, then VFR today and tonight. Low threat for
a -shra or -tsra over the mountains and just south of the airport,
but won`t include in the taf at this point.
At KCOS...LIFR cigs/vis this morning will be slow to lift and clear
as se surface winds persist into the afternoon. Expect LIFRvis in
fog to improve first, though IFR cigs will remain in place until
afternoon. Perhaps a brief period of MVFR from late afternoon into
the evening as lower clouds burn off, but given continued SE winds,
model clearing trends are usually too quick and will in general keep
forecast on the pessimistic side for now.
At KPUB...IFR cigs have been rather variable so far this morning,
though given weak east surface wind would expect at least a few
hours of IFR/LIFR cigs through the morning, gradually improving to
MVFR during the afternoon.
Over the eastern mountains and plains, areas of IFR cigs and
mountain obscuration will persist today and tonight, while farther
west toward the Continental Divide, VFR conditions will dominate.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...LW